RasterSource

class RasterSource

Bases: ABC

A source of raster data.

This should be subclassed when adding a new source of raster data such as a set of files, an API, a TMS URI schema, etc.

Attributes

bbox	Bounding box applied to the source imagery.
crs_transformer	Associated CRSTransformer.
dtype	numpy.dtype of the chips read from this source.
extent	Extent of the RasterSource.
num_channels	Number of channels in the chips read from this source.
shape	Shape of the raster as a (height, width, num_channels) tuple.

__init__(channel_order: Optional[List[int]], num_channels_raw: int, bbox: Box, raster_transformers: List[RasterTransformer] = [])

Constructor.

Parameters

• channel_order (Optional[List[int]]) – list of channel indices to use when extracting chip from raw imagery.

• num_channels_raw (int) – Number of channels in the raw imagery before applying channel_order.

• bbox (Box) – Extent or a crop of the extent.

• raster_transformers (List[RasterTransformer]) – RasterTransformers for transforming chips whenever they are retrieved. Defaults to [].

Methods

__init__(channel_order, num_channels_raw, bbox)	Constructor.
get_chip(window[, out_shape])	Return the transformed chip in the window.
get_chip_by_map_window(window_map_coords[, ...])	Same as get_chip(), but input is a window in map coords.
get_raw_chip(window[, out_shape])	Return raw chip without applying channel_order or transforms.
resize(chip[, out_shape])
set_bbox(bbox)	Set self.bbox to the given value.

__getitem__(key: Any) → ndarray

Parameters

key (Any) –

Return type

ndarray

__init__(channel_order: Optional[List[int]], num_channels_raw: int, bbox: Box, raster_transformers: List[RasterTransformer] = [])

Constructor.

Parameters

• channel_order (Optional[List[int]]) – list of channel indices to use when extracting chip from raw imagery.

• num_channels_raw (int) – Number of channels in the raw imagery before applying channel_order.

• bbox (Box) – Extent or a crop of the extent.

• raster_transformers (List[RasterTransformer]) – RasterTransformers for transforming chips whenever they are retrieved. Defaults to [].

get_chip(window: Box, out_shape: Optional[Tuple[int, int]] = None) → ndarray

Return the transformed chip in the window.

Get a raw chip, extract subset of channels using channel_order, and then apply transformations.

Parameters

• window (Box) – The window for which to get the chip.

• out_shape (Optional[Tuple[int, int]]) – (height, width) to resize the chip to.

Returns

Array of shape (…, height, width, channels).

Return type

np.ndarray

get_chip_by_map_window(window_map_coords: Box, out_shape: Optional[Tuple[int, int]] = None) → ndarray

Same as get_chip(), but input is a window in map coords.

Parameters

• window_map_coords (Box) –

• out_shape (Optional[Tuple[int, int]]) –

Return type

ndarray

get_raw_chip(window: Box, out_shape: Optional[Tuple[int, int]] = None) → ndarray

Return raw chip without applying channel_order or transforms.

Parameters

• window (Box) – The window for which to get the chip.

• out_shape (Optional[Tuple[int, int]]) –

Returns

Array of shape (…, height, width, channels).

Return type

np.ndarray

resize(chip: ndarray, out_shape: Optional[Tuple[int, int]] = None) → ndarray

Parameters

• chip (ndarray) –

• out_shape (Optional[Tuple[int, int]]) –

Return type

ndarray

set_bbox(bbox: Box) → None

Set self.bbox to the given value.

Note

This method is idempotent.

Parameters

bbox (Box) – User-specified bbox in pixel coordinates.

Return type

None

property bbox: Box

Bounding box applied to the source imagery.

abstract property crs_transformer: CRSTransformer

Associated CRSTransformer.

abstract property dtype: dtype

numpy.dtype of the chips read from this source.

property extent: Box

Extent of the RasterSource.

property num_channels: int

Number of channels in the chips read from this source.

property shape: Tuple[int, int, int]

Shape of the raster as a (height, width, num_channels) tuple.